AACM’s founding fathers pianists Muhal Richard Abrams and Jodie Christian, drummer Steve McCall and trumpeter Phil Cohran had sent out postcards inviting leading Chicago musicians to meet on May 8, 1965, at Mr. Cohran’s South Side home to set the AACM’s course and credo. The AACM has long offered sustenance and support to musicians steeped in Jazz tradition yet unwilling to be confined by it. Through a half-century, the organization has grown from a collective of ambitious Chicago musicians to an engine of creative inspiration and practical outreach that has touched nearly all corners of modern music.

A Power Stronger Than Itself: The AACM and Experimental Music, a 2008 book by trombonist and composer George Lewis, also an important force in the AACM ranks. Mr. Lewis’s book framed the conditions that gave rise to this movement: A legendary South Side jazz and blues scene quickly evaporating; creative ferment demanding a broader jazz aesthetic; a transformation of African-American identity and its representations; and, above all, a dedication to wherever collective purpose and individualized composition might lead gifted musicians in a troubled yet genre-free world.

Well beyond Chicago, the AACM (which includes a New York chapter, formed in the late 1970s by Mr. Abrams and pianist Amina Claudine Myers, among others) holds a singularly celebrated place. Its key members form a roll call of distinguished African-American musicians, with National Endowment for the Arts Jazz Master Fellowships, MacArthur Foundation grants and prestigious academic appointments: Mr. Abrams, still a formidable creative force at 84, whose early-1960s Experimental Band helped foster the organization; Mr. Lewis, now 62, the Edwin H. Case professor of American music at Columbia University; and, among others, multireedists Anthony Braxton, Joseph Jarman, Henry Threadgill and Mr. Mitchell, and trumpeters Wadada Leo Smith and the late Lester Bowie. These musicians’ individual expressions sound nothing alike, yet their careers trace a shared ascendance.

Show engineered, produced, hosted, and edited by Joyce Jones. Listen for our On the Bandstand segment with NYC metro area appearances of Suga’ guests at the end of the first hour with Associate Producer Hank Williams.

AACM’s New York chapter is celebrating their 50th anniversary with talks and performances every Friday night in October starting on the 9th at the Community Church of New York on E 35th St. Full schedule and details are at the AACM New York website.